The invention relates to a photographic copying apparatus and, more particularly, to such an apparatus having a light chute arrangement of the type having reflective inner surfaces for conveying light from a light source to an original.
Light chutes are essentially compartments which convey light in a path from a light source to an original, i.e., an object to be illuminated, such as a negative. Such light chutes have been utilized in color copier apparatus to convey the variously-colored, filtered light components from their respective light sources to illuminate a negative. The light chute receives and mixes various light components and serves to uniformly distribute the latter over the entire area of the negative.
Difficulties have arisen in the optimal illumination of negatives of different respective sizes. In order to illuminate each of the differently-sized negatives with maximum intensity, it is necessary to provide a light chute having a correspondingly-sized cross-section.
The prior art has attempted to present different cross-sectioned light chutes for the different sizes of respective negatives. Thus, it is known to arrange a sliding carriage having a plurality of light chutes which are each respectively displaceable into the light path. However, this approach has the disadvantage that it requires a comparatively large amount of space. This prior art approach takes up a great deal of room since it must accommodate all possible positions of the sliding carriage.
In addition, the prior art has proposed a light chute arrangement in which the walls of an initially large-sized chute are each partially displaced inwardly towards each other in order to form a smaller-sized cross-section. However, this latter approach have the disadvantage that it requires all four walls to be moved. Thus, each of the walls must be separately positioned which means that this arrangement requires a complicated mechanism to move each of the respective walls. This latter prior art approach also suffers from the disadvantage that the number of possible cross-sections is limited.